VIRUSES Is a tiny particle that needs a host cell to reproduce and multiply. They are neither alive nor dead… but most scientists consider viruses nonliving particles, since these are NOT cells.

VIRUSES The organism or cell where a virus multiplies is called a HOST. It provides all the energy the virus needs to reproduce. The virus is a parasite to the host.

VIRUSES Viruses vary in shape and size: they can be round, robot like or shaped as bullets. They can measure between 20 and 200 nanometers. 1 nm = 1 billionth of a meter Structure: - a protein coat for protection: it allows the virus to attach to the host’s cells. - an inner core made of genetic material

VIRUSES H OW DO THEY MULTIPLY ? ACTIVE VIRUS also called LYTIC CYCLE The virus attaches to the host cell, injects its genetic material, and takes over the functions of the host cell. Once this is done, the host cell starts producing the virus’ proteins and genetic material. These parts will form new viruses, the host cell will burst and the new viruses will go on to infect other cells.

VIRUSES H OW DO THEY MULTIPLY ? HIDDEN VIRUS also called LYSOGENIC CYCLE The virus attaches the cell and injects its genetic material. This genetic material will become part of the genetic material of the host cell. When time passes, the genetic material gets “free” and enters the lytic cycle.

BACTERIA They were discovered in 1600 by Anton van Leeuwenhoek. H OW ARE BACTERIA CELLS DIFFERENT ? Bacteria are PROKARYOTES. Most have a cell wall for protection. All have a cell membrane that decides what goes inside and outside of the cell. They also have ribosomes, where proteins are produced. Some bacteria have a flagellum for movement.

BACTERIA H OW ARE BACTERIA CELLS DIFFERENT ?

BACTERIA H OW ARE BACTERIA CELLS DIFFERENT ?... 1.Spherical 2.Rod like 3.Spiral SHAPESIZE They can vary in size, but mainly they are very small.

BACTERIA W HAT DO THEY NEED TO SURVIVE ? There are some bacteria that are autotrophic: - There are ones that use the energy from the sun (like plants) - There are others that use the energy from chemical substances.

BACTERIA W HAT DO THEY NEED TO SURVIVE ? There are some bacteria that are heterotrophic: - They consume other organisms or the food that they make.

BACTERIA H OW DO THEY REPRODUCE ? Under the right conditions, bacteria can reproduce every 20 minutes! Sexual Reproduction Asexual Reproduction

BACTERIA H OW DO THEY REPRODUCE ?... Asexual Reproduction Binary Fission: one cell divides to form two identical cells. This process involves only ONE parent, and its offspring is identical.

BACTERIA H OW DO THEY REPRODUCE ?... Sexual Reproduction Conjugation: one bacterium transfers some of its genetic material to another bacterium. The result is a bacterium with new combinations of genetic material. This process doesn’t increase the number of bacteria.

BACTERIA R OLES IN NATURE … Oxygen and food production: autotrophic bacteria produce oxygen. In the case of food, some undergo fermentation for different products such as cheese and yogurt Recycling: are decomposers. Brake down large chemicals into smaller ones. Return basic chemicals to the environment to reuse. Medicine production: In the intestine for food digestion. In 1970s for production of insulin for people that have diabetes.

PROTISTS Are eukaryotes that live in moist surroundings and are very diverse. Most of them are UNICELULLAR, although there are exceptions. They can be heterotrophic or autotrophic or both.

PROTISTS A NIMAL - LIKE P ROTISTS OR P ROTOZOANS Are heterotrophic Most of them are able to move to obtain their food. Unicellular

PROTISTS A NIMAL - LIKE P ROTISTS OR P ROTOZOANS … 1.Sarcodines: they forms pseudopods or false foots (AMOEBA) 1.Ciliates: have cilia that are hair like projections (PARAMECIUM) 1.Flagellates: use whip like flagella to move. Some of them live in other organism’s body. Ex: symbiosis with termites 1.Parasites: feed on their host (Plasmodium)

PROTISTS P LANT – LIKE P ROTISTS Commonly called algae Are autotrophic Some are unicellular and others multicellular or live in colonies They can be green, brown, red and yelow

PROTISTS P LANT – LIKE P ROTISTS Diatoms: unicellular, are food for heterotrophs Dinoflagellates: unicellular, different colors, two flagella, glow in the dark Euglenoids: green, unicellular, found in fresh water and can act as heterotrophs.

PROTISTS P LANT – LIKE P ROTISTS Red algae: multicellular, absorb small amount of light that reaches deep ocean waters Green algae: most are unicellular, some form colonies. Live in fresh or salt water; are closed related to plants… Brown algae: have plant like structures; form underwater “forests”

PROTISTS F UNGUS – L IKE P ROTISTS Are heterotrophic, have cell wall, use spores to reproduce Types: Slime molds: brilliantly colored; live in moist places; feed on bacteria and other microorganisms Water molds and Downy Mildews: grow as tiny threads that look like fuzz. Attack food crops

FUNGI W HAT ARE THEY ? Are eukaryotes that have cell wall. Are heterotrophic: they absorb their food Use spores to reproduce Need moist warm places to grow

FUNGI C ELL S TRUCTURE Except for unicellular yeast, cells are arranged in structures called hyphae. These hyphae are threadlike tubes that make up the bodies of multicellular fungi. In some fungi hyphae are loosely tangled. In others hyphae are packed tightly together.

FUNGI R EPRODUCTION Reproduce by making spores, which are surrounded by a protective covering and can be easily transported through air or water. The spores are produced in the fruiting bodies, and their appearance may vary depending on the fungus. In some: the visible part of the fungus. In others (bread molds), fruiting body is tiny stalk like hyphae.

FUNGI R EPRODUCTION Asexual Reproduction: Under right conditions of moisture and food fungi make spores asexually. BUDDING: no spores produced. A small yeast cell grows from the body of a parent cell (think of a tree branch). The new cell breaks and lives on its own.

FUNGI R EPRODUCTION Sexual Reproduction: Under unfavorable conditions of moisture and food fungi reproduce sexually. The hyphae of two fungi grow together and genetic material is exchanged. In time, a new reproductive structure grows and start producing spores. The fungi that grow from these spores are genetically different from the parents.

FUNGI C LASSIFICATION Sac Fungi: Largest group of fungi Produce spores is structures like long sacs Includes yeasts, morels and truffles

FUNGI C LASSIFICATION Club Fungi: Produce spores is structures like clubs Includes mushrooms, bracket fungi and rusts (roya) The most poisonous are club fungi

FUNGI C LASSIFICATION Zygote Fungi: Produce resistant spores: can survive in extreme conditions Includes molds (Rhizopus), and molds that attack insects.

R OLES IN NATURE … Food production: They cause the bread to rise. Otherwise it would be flat. Recycling: are decomposers. Brake down large chemicals from dead organisms. Return basic chemicals to the environment to reuse. Medicine production: Penicillium. Alexandre Fleming found that no bacteria grew near the mold. Diseases: are parasites for plants and animals. FUNGI

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References qNym46AFSoe6PxSggLxEjw9fXbmaaLRa7M9WN9zZTGO1_h0Rd_POA qNym46AFSoe6PxSggLxEjw9fXbmaaLRa7M9WN9zZTGO1_h0Rd_POA VsmPtm94pPN78S7H4X7WRHr0aAbdZzazsKb5yAg0mAvHw VsmPtm94pPN78S7H4X7WRHr0aAbdZzazsKb5yAg0mAvHw ZAFoTksyi70A0hW3wod ZAFoTksyi70A0hW3wod KciIpqpUox_zmTngDD9j3pvfp6eF3YedKfDZQiPT0yZ51Y KciIpqpUox_zmTngDD9j3pvfp6eF3YedKfDZQiPT0yZ51Y 8eIkd-UuUvkNwgw8oekU6dg 8eIkd-UuUvkNwgw8oekU6dg Jenner, J et. al Science Explorer From Bacteria to Plants. Ed. Pearson Prentice Hall Purves, et al Vida, la Ciencia de la Biología.